Releasable coupling assembly

Abstract

A lock that includes a wedge that is used to releasably secure separable components of an assembly together. The wedge can be used with a spool. The wedge and spool are threadedly coupled together to drive the wedge into and out of an opening in the assembly without hammering or prying. The direct coupling of the wedge and spool eliminates the need for bolts, washers, nuts and other hardware so as to minimize the number of parts. As a result, the lock is inexpensive to make, easy to use, and unlikely to become inoperative because of lost or broken parts or due to fines or other difficulties encountered in harsh digging environments. Further, the wedge can be driven into the assembly to provide the degree of tightness necessary for the intended operation and/or to re-tighten the assembly after incurring wear during use. A latch assembly is preferably provided to securely hold the wedge in place and avoid an undesired loss of parts during use.

1. A lock adapted for receipt into an opening defined by two separable components in a wear assembly for excavating equipment, the lock comprising:
 a wedge having a first end, a second end, a longitudinal axis extending centrally through the first and second ends, and a rounded exterior surface about the longitudinal axis that tapers toward the first end for initial receipt into the opening, the exterior surface including a helical groove; and 
 a spool including a body and arms at opposite ends of the body, each arm including an inner surface that tapers outward in a rearward direction, a trough on the body having a generally concave surface for receiving the wedge, and a series of helical ridges in spaced apart relation along the trough to engage the helical groove on the wedge; 
 the wedge and the spool being threadedly coupled together in the opening by the engagement of the ridges in the helical groove such that rotation of the wedge about the longitudinal axis translates the wedge in the opening in a direction generally parallel to the longitudinal axis and along the trough of the spool to tighten the lock in the opening thereby causing the wedge and the spool to press the separable components in opposite directions to hold the two components together. 
 
     
     
       2. A lock in accordance with  claim 1  further including a tool receiving formation on the second end for rotating the wedge. 
     
     
       3. A lock adapted for receipt into an opening defined by two separable components in a wear assembly for excavating equipment, the lock comprising:
 a wedge having a first end, a second end, a longitudinal axis extending centrally through the first and second ends, and a rounded exterior surface about the longitudinal axis that tapers toward the first end for initial receipt into the opening, the exterior surface including a helical groove; and 
 a spool including a trough having a generally concave surface for receiving the wedge, and a series of helical ridges in a spaced apart relation along the trough to engage the helical groove on the wedge; 
 the wedge and the spool being threadedly coupled together in the opening by the engagement of the helical ridges in the helical groove such that rotation of the wedge about the longitudinal axis translates the wedge in the opening in a direction generally parallel to the longitudinal axis and along the trough of the spool to tighten the lock in the opening thereby causing the wedge and the spool to press the separable components in opposite directions to hold the two components together. 
 
     
     
       4. A lock in accordance with  claim 3  wherein the spool includes a body and arms at opposite ends of the body, each said arm including an inner surface that tapers outward in a rearward direction. 
     
     
       5. A lock in accordance with  claim 3  further including a tool receiving formation on the second end of the wedge for rotating the wedge. 
     
     
       6. A lock in accordance with  claim 3  wherein the spool includes a body and aims at opposite ends of the body extending away from the trough. 
     
     
       7. A lock in accordance with  claim 3  wherein the wedge includes a spiral land segment between adjacent turns of the groove, and the land segment defines a first bearing surface to contact one of the separable components and an opposite second bearing surface to contact the trough of the spool to thereby resist loading between the components and prevent separation of the separable components. 
     
     
       8. A lock in accordance with  claim 7  wherein the width of the land segment is larger than the width of the groove. 
     
     
       9. A lock in accordance with  claim 3  wherein the groove in the wedge has a width that narrows as the groove extends from the first end toward the second end along a length of groove that engages the helical ridges of the spool. 
     
     
       10. A lock in accordance with  claim 3  wherein the groove has a width and a pitch, and the width is about one-eighth of the pitch. 
     
     
       11. A lock in accordance with  claim 3  wherein the groove extends along the wedge at an angle, and the angle changes to become more shallow as the groove extends toward the second end. 
     
     
       12. A wear member for excavating equipment comprising a front end, a rear end, converging walls that converge toward the front end, side walls extending between the converging walls, a socket that opens in the rear end to receive a nose fixed to the excavating equipment, an opening extending through one of said walls to communicate with the socket, and a resiliently biased latch projecting into the opening and defining a thread formation to engage a threaded wedge to secure the wear member to the nose. 
     
     
       13. A wear member in accordance with  claim 12  which further includes a cavity for receiving the latch, and wherein the latch includes a body defining the thread formation and a resilient member to bias the latch outward. 
     
     
       14. A wear member in accordance with  claim 13  wherein the thread formation on the body includes a helical ridge. 
     
     
       15. A wear member in accordance with  claim 14  wherein the opening includes a series of spaced apart helical ridges on a wall of the wear member in alignment with the helical ridge on the body to engage a groove in the wedge. 
     
     
       16. A wear member in accordance with  claim 13  wherein the thread formation includes a ridge shaped as a spiral segment. 
     
     
       17. A wear member in accordance with  claim 12  wherein the thread formation includes a ridge shaped as a spiral segment. 
     
     
       18. A wear member in accordance with  claim 12  wherein the thread formation includes a series of helical ridges in a spaced apart relation along the trough to engage a helical groove on the wedge. 
     
     
       19. A wear member in accordance with  claim 18  wherein a span of a wall of the wear member in the opening between each of the adjacent ridges defines a bearing surface to bear against a complementary land segment defined on the wedge. 
     
     
       20. A wear member in accordance with  claim 18  wherein the ridges each has a first width and the bearing surfaces each has a second width extending between the adjacent ridges, and wherein the second width is substantially larger than the first width.